Mounting of gas turbine units



Dec. 8, 1953 J. o. P. HUGHES ErAL 2,661,593

MOUNTING OF GAS TURBINE UNITS Filed Sept. 2, 1949 o m N m N ul a: I E

o. m 7 L0 m N LO 4 Sheets-Sheet l Dec. 8, 1953 Y J. o. P. HUGHES ETAL 2,661,593

MOUNTING OF GAS TURBINE UNITS Filed Sept. 2, 1949 4 Sheets-Sheet 2 Dec. 8, 1953 J. o. P. HUGHES ETAL 2,561,593

MOUNTING OF GAS TURBINE UNITS Filed Sept. 2, 1949 4 Sheets-Sheet 3 Dec. 8, 1953 J. o. P. HUGHES ET AL MOUNTING 0F. GAS TURBINE UNITS Filed Sept. 2, 1949 4 Sheets-Sheet 4 N. UE

m2 8 me i.

Patented Dec. 8, 1953 MOUNTING F GAS TURBINE UNITS John Oliver Philip Hughes and Paul Heinz Walter Wolif, Rugby,

England, assignors to The English Electric Company Limited, London, England, a British company Application September 2, 1949, Serial No. 113,883

Claims priority, application Great Britain September 8, 1948 6 Claims.

The invention relates to the mounting of gas turbine units in general, and in gas turbine driven locomotives in particular.

According to the invention a rigid unit, consisting of at least one turbine and compressor therefor, is attached by means of metal bonded rubber bushings arranged substantially in one plane at or near the centre of gravity of the said unit, transverse to the axis thereof, preferably, but not necessarily, with an auxiliary metal bonded rubber bushing or bushings arranged in a direction parallel to the axis of the unit at or near one end of the unit.

As metal bonded rubber bushings offer a comparatively high resistance to deflection in a direction perpendicular to their axis (which is taken by the rubber in compression and tension, respectively) than in the direction of their axis (Which is taken by the rubber in shear), such an arrangement provides a good location of the set in alignment with its output shaft while allowing for the thermal expansion of the set in operation.

As the metal bonded rubber bushings preserve their desirable resilient and damping characteristics only up to a certain maximum temperature, say 70 C., the metal bonded rubber bushings or at least some of them, are cooled according to a preferred subsidiary feature of the invention.

According to a development of the invention, a gas turbine unit comprising a heat exchanger the hot pass of which is passed by the exhaust gases of the turbine, and the cold pass of which is passed by the compressed air on its way from the compressor to the combustion chamber, is suspended as a whole in the manner hereinabove described, the heat exchanger being attached to the said unit at its front by means of the compressed air pipes from the compressor and to the combustion chambers, and at its rear to the horizontal radial engine bearers of the said unit by means of cantilever booms rigidly connected to these attachments and extending towards the rear end of the heat exchanger which rests on them by means of a spring having a fiat loaddeflection characteristic, and preferably also of metal bonded rubber cushions, the suspension allowing a horizontal movement of the said heat exchanger with respect to the said booms at their points of connection.

In order that the invention may be better understood and readily carried into eifect, some embodiments thereof will now be described by way 0f example with reference to the accompanying drawings, in which:

Fig. l is a side elevation of a gas turbine unit.

Fig. 2 is an end elevation thereof as seen in the direction of the arrow A of Fig. 1.

Fig. 3 is a cross section on the line 33 of Fig. 1 through one of the horizontal radial engine bearers of the gas turbine unit on a larger scale.

Fig. 4 is a longitudinal section through the subsidiary engine mounting at the front end of the gas turbine set, on the same scale as Fig. 3.

Fig. 5 is a side elevation of a gas turbine unit.

Fig. 6 is an end elevation thereof as seen in the direction of the arrow A of Fig. 5.

Fig. '7 is a horizontal cross section on the line l-l of Fig. 5 through one of the horizontal radial engine bearers of the gas turbine unit on a larger scale.

Fig. 8 is a side elevation, and

Fig. 9 is an end elevation of a detail of Figs. 5 and 6 seen in the same directions as on these figures but on a larger scale.

Referring first to Figs. 1-4, the gas turbine of this embodiment (Figs. 1 and 2) is of the kind forming the subject of patent application Ser. No. 76,335 filed on February 14, 1949, now abandoned, comprising a multi-stage compressor arranged in a casing 56, I 2 coupled with a gas turbine driving it and arranged in a casing 53, with an independent power output turbine arranged in alignment therewith in the casing 54. 29 is the air intake into the compressor at the front end of the set, 50 the compressed air duct from the compressor output to the top of the heat exchanger iii, 62 are the two symmetrically arranged combustion chambers connected with the bottom of the heat exchanger 5! and, by the elbows 52, with the entrance l2a of the gas turbine casing 53, 55 is the turbine exhaust elbow connected with the bottom of the heat exchanger, and 28 is the discharge funnel therefrom.

This gas turbine unit is supported in the metal bonded rubber bushings i, 2 and 3 radially arranged with respect to the axis of the unit in a vertical plane substantially through the centre of gravity C. G. of the unit.

By the reasons given above, these bushings offer comparatively little resistance to radial thermal expansions of the turbine casing while they effectively restrain this casing from turning about its axis, moving fore or aft (these two movements being resisted by all three bushings I, 2 and 3), up or down or yawing' about a vertical axis (restricted by the bushings I and 2),

and right or left or pitching about a transverse axis (resisted by the bushing 3).

Preferably there is an additional metal bondedrubber bushing l arranged parallel to the axis of the unit, at the air intake casing 29 which by the same reason does not resist materially any longitudinal thermal expansion of the unitbut,.due to its long leverage from thecentre'of gravity, essentially adds to restraining any yawing or pitching movement, and. to a small extent also rotation about the axis of the unit.

The combined compressor anli'turbine casing 2954 forms the rigid basis 'of th;e:.unitito=which the combustion chambers 82 an'cl the heat exchanger i are attached, while the exhaust'elbow 55 of light construction is not intended as a structural load carrying element.

Referring now to Fig. 3, 5 is part ofithetma-in power tur ine casing, which carries a flange 5 to which the engine bearer 6 is flanged. The metal bonded rubber bushing i is fittediwith its inner shell 1 to the reduced portion 6 of the engine bearer 5, while theouter-shellil isprovi'ded for being fit ed into'the socket ofipartof the outer supporting structure, saytheframework of a locomotive.

A chamber i3 provided in theiiangecl portion of 'the engine bearer 5 which is adapted to be connected "with the coolant, preferably cool air underpressure. A n'urnbenof bores :Q (of which one only is shown) are arranged in the-casting of the turbine casingfi i in order to deliver this air, after :it has performed its taskas a coolant, into the m-ain'gas stream of the turbine. Abore iii is arranged in the rerluced portion i *of the engine'bearerin order to reduce the cross section available to the flow of heat-from the tur bine casing towards the rubber bushing i. This bore it is preferably opening "outwards to allow the ac ess of cool air irorn the atmosphere.

Referring nowto Fig.4, theauxiliary rubber bushing i is bonrledto an inner shell ii adapted to be fitted on a spigot of'theouter supporting structure and 'a flanged outer shell 1 2 attached by means of bolts i l and'nutsioto a flange'lii, in turn fixed to the compressor air intake 29. Auxiliaries to the compressor are schematically indicated at it.

Referring now to modified generalzarrangernent shown in Figs. fi and fiythe-development of this arrangement consists mainlyin' that a cantilever bocrn it is attached with its flanges 22 (see also Fig. 7) to the flange 6 of each engine bearer on both sides of the gas turbine .unit.

The free ends of these booms *irlcarrybraolrets i; on each of which a metal bonded rubberpad i8 is attaches; with its lower 'metali'plate (seealso Fl '5. 8 and 9); the upper metal plate :or each rubber pad is attached toa plate '59 at the end of an inverted semi-elliptic spring '59 theicentre of which is attached. to a bracket 8 atth'e rear of the heat exchanger 5 i.

The weight of the heat exchanger BI 'is thus carried partly by the connectine'ipipesto the combustion chambers and the pipe on from the compressor 56 andpartly by-the spring anucantilever boom arrangement described hereinabove. Thus the weight of the heat exchanger xfiliseventually transmitted to the engine bearers and :re-- sili'ent bushings i and 2 supported. by-the base-of the power plant, such asthe main frame ofta locomotive.

Difierential thermal expansion in the vertical direction is taken by the deflection of th'etsemielliptic spring which is preferably :given :a hat load characteristic, i.'e. wherein theiload does not vary substantially'with the'tdeiiection. Differential thermal expansionsin thehorizontal plane bearinglnot shown) is connected to the casing as by ir-adi'ali. spokes ihtof aerofoil cross section the outer'pa'rtpnly of-a'horizontal spoke being shown.

Thecasingtit has sockets Hi5 integral with it enclosing a cavity E55 and carrying a flange M35 towhichtheengine bear r Hit is flanged. A shim 86 of metal, or preferably of heat insulating ..material is interposed between the flanges the and We. The reduced portion ice or" the engine bearer :h'as a central bore lit in order to restrict the cross section available to the flow of heat from the turbine casing towartis the rubber bushing ill! whichis fitted'to the portion 5% with its inner shell uu, preferably with a heat insulating bush ll of asbestosor the like interposed. The outer shell lot of the rubber bushing lei is arranged'for being fitted into'the socket of part of the outer supporting structure, say the framework of a locomotive.

The-flange E2 of thecantilever boom it bolted tothefianges i 35 and 5%, with a toroid recess l3 left between the inner'parts of the flanges ii and Cooling air is blown from outside through a socket i i into this recess 73 from where it can escape through the openings '55 and in the flange #2 or through the bores it and-i is of the reduced portion 5 as of the engine bearer.

Separate cooling air for the turbine'main bearing may be blown through'the ducts 589 in'the spokes are of the'part ei'of the casing whereby theinflux of heat into the socket let carrying the flange m5 is reduced.

If desired, the bore Ht may be closed-outside and the shim 12%" maybe perforated, so that the same air stream, after having cooled theengine bearer is passed through thebores its as part of the cooling medium for the turbineinain bearing.

Vv'hapt we claim-as our invention and desire to secure by Letters Patent is:

1. For a gas turbine plant including at least one turbine, the compressor and at least one combustion chamber'thereior all forming a rigid unit, and 'alheat exchanger, a mounting comprisingzin combination: a pair of metal bonded rubber bushings arranged Jopposite one another on a horizontal diameter of the said unit, another metal bonded. bushing arranged on a radius perpendicular to said diameter substantially inth'e sanievertical plane acliacent the centre of gravity of the said unit, compressed air tubes rigidly connecting the front end of the said heat exchanger with the said combustion chamber and. compressona pair of cantilever booms attached to the said rigid unit adjacent the said diametrically arranged bushings, and sping means supporting the said heat exchanger the free 'ends of the said cantilever booms.

'2. A mounting .as claimed. in claim 1 comprisingin addition a pair of metal bonded rubber pads supporting said spring means on the free ends of the said cantilever booms, and wherein thel 'aid spring means'is an inverted semi-ellipcal leaf spring having a flat load oharacter istio, attachedwith its middle to the middle of the rear end of the said heat exchanger transversely to the axis of the said unit, and resting with its free ends on the said metal bonded rubber pads, the said spring allowing for differential thermal expansion of the said heat exchanger and the said rigid unit in a vertical direction, and the said metal bonded rubber pads allowing for diiferential thermal expansion of the said heat exchanger and the said rigid unit in the horizontal plane.

3. For a gas turbine plant including at least one turbine and the compressor therefor forming a rigid unit, a mounting comprising in combination: brackets attached to the said rigid unit substantially in the same plane perpendicular to the axis and adjacent to the centre of gravity thereof, engine bearers having a heat conductive path of a reduced cross section area of metal available from the said brackets through the said engine bearers, cooling means cooling the said engine bearers, and metal bonded rubber bushings attached to the said engine bearers and supporting the said rigid unit in the said plant, the said reduced heat conductive cross section area and the said cooling means providing a, minimum of conduction of heat to the said rubber bushings.

4. A mounting as claimed in claim 3, comprising in addition a layer of heat insulating material arranged between the said brackets and the said engine bearers.

5. A mounting as claimed in claim 3, comprising in addition a layer of heat insulating material arranged between the said engine bearers and the said metal bonded rubber bushings.

6. A mounting as claimed in claim 3, comprising as the said cooling means, passages through the said engine bearers arranged for serving as conduits for a flow of a coolant.

JOHN OLIVER PHILIP HUGHES. PAUL HEINZ WALTER. WOLFF.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,778,503 Lord Oct. 14, 1930 1,862,484 Lord et a1 June 7, 1932 2,193,332 Hasbrouck Mar. 12, 1940 2,369,795 Plam'ol et a1. Feb. 20, 1945 2,403,388 Morey et al July 2, 1946 2,443,054 Putz et a1 June 8, 1948 2,481,547 Walker et a1 Sept. 13, 1949 2,529,955 Morley Nov. 14, 1950 OTHER REFERENCES Ser. No. 288,972, Julien et al. (A. P. C.), published May 25, 1943. 

